JPH04114744A - Deodorizing catalyst and heating apparatus using the same - Google Patents

Abstract

PURPOSE:To enhance release resistance and the low temp. activity of an Ag/Mn type deodorizing catalyst by supporting an active component containing silver and manganese or compounds of them on a porous material such as cordierite having specific pore distribution. CONSTITUTION:A deodorizing catalyst is obtained by supporting an active component containing silver and manganese or compounds of them on a porous material composed of cordierite, mullite or alumina having pore distribution wherein the total pore volume is 0.20cm<3>/g or more and the sum amount of the volume of pores whose radius is 1000-30000Angstrom is 80vol.% of the total pore volume. A heating apparatus can be constituted by arranging the aforementioned deodorizing catalyst to an exhaust part. Since the active component is directly supported on the porous material, the release of the catalyst from the porous material is prevented. Further, the deodorizing catalyst has deodorizing activity at relatively low temp. and,can reduce or remove the offensive smell component contained in the smoke or exhaust gas generated from a heating apparatus such as a food cooker, a dust incinerator or a coating apparatus.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is a heating bag for cooking appliances, garbage incinerators, painting equipment, etc.! The present invention relates to a deodorizing catalyst thereof, and particularly to a deodorizing catalyst suitable for reducing and removing flammable organic odor components generated from food products, garbage, etc. during processing.

[Prior Art] One of the problems with using food cooking appliances such as ovens and stoves is that malodorous components contained in smoke and exhaust gas generated from food heated in the cooking appliance or from food particles can enter the house. It spreads and is adsorbed to furniture, walls, carpets, etc., emitting a bad odor for a relatively long period of time. As a countermeasure to this problem, many modern food cookers are equipped with devices that suck the generated smoke and exhaust gas, bring it into contact with a catalyst, and oxidize the malodorous components to eliminate and reduce the amount of malodorous components.

Silver (
It is known that a catalyst combining Ag) and manganese (Mn) exhibits excellent low-temperature activity (Kozo Tabe, Tetsube Kiyoyama, Kazuo Fueki, eds., Metal Oxides and Composite Oxides, 197
8.4.20 Kodansha Scientific, p. 16), this type of catalyst is usually coated with a high specific surface area support such as activated alumina on a high strength and heat resistant base material with a specific surface area of several m2/g or less. It is prepared by wash-coating and then supporting the catalyst component by a crushing method or the like.

[Problem M to be Solved by the Invention] However, depending on the conditions of use, the catalyst layer obtained by combining Ag and Mn obtained by the above-mentioned preparation method may peel off. Particularly when used in food cooking ovens, etc., it has been a big problem that the peeled off catalyst falls on the food.

In addition, the A g / M n type catalyst is generally heated at 300°C.
Since it performs its function at a nearby temperature, it usually has a catalyst or a mechanism to preheat the smoke or exhaust gas to be treated. However, due to this preheating, in the case of a food cooking device, 30% to 40% of its power consumption is consumed for preheating smoke and exhaust gas. Furthermore, the preheating mechanism and its surrounding insulation require a large volume inside the device, which is one of the obstacles to making the device smaller and lighter.

Therefore, an object of the present invention is to improve the peeling resistance and low-temperature activity of an Ag/Mn-based deodorizing catalyst, and to reduce or omit the preheating mechanism of the deodorizing catalyst.

[Means to solve the problem] The above object of the present invention is achieved by the following configuration.

In other words, in deodorizing catalysts that reduce or remove odor components contained in smoke and exhaust gas generated from heating equipment such as food cookers, garbage incinerators, and painting equipment, active ingredients containing silver and manganese elements or their compounds are used. , the total pore volume is 0, 20 cm3/'g or more, and the total volume of pores in the radius range from 1,000 to 30,000 is 80V of the total pore volume.

A deodorizing catalyst supported on a porous material such as cordierite, mullite, alumina, etc. having a pore distribution of 1% or more, or a heating device in which the deodorizing catalyst is disposed in an exhaust section.

[Function] The deodorizing catalyst of the present invention does not use a wash coat,
Since the catalyst is directly supported on a porous material made of cordierite, mullite, alumina, etc. having the above-mentioned total pore volume and pore distribution, the catalyst does not peel off from the porous material.

Further, the deodorizing catalyst has deodorizing activity at a relatively low temperature,
Odor components contained in smoke and exhaust gas generated from heating devices such as food cookers, garbage incinerators, and painting equipment can be reduced or removed.

[Example] Examples and comparative examples of the present invention will be described with reference to the drawings.

Although cordierite honeycomb was used as the catalyst carrier in the present examples and comparative examples, the present invention is not limited to this.
Porous materials such as mullite and alumina can also be used.

In addition, the shape of the porous material may be granular, spherical, or
It may be plate-shaped or the like. In addition, in this example, the total pore volume and pore distribution of the honeycomb were measured using a mercury porosimeter with a pore radius of 2.
The measurements ranged from 50 μm to 30 people.

FIG. 1 shows the shape of a cordierite honeycomb 1 with a cell density of 200 cells/1 nch2 used in the deodorizing catalysts of Examples and Comparative Examples. Dimensions are width 150mm, height 4
0 mm, and the length in the cell direction is 20 mm.

Example 1 Honeycomb A with a total pore volume of 0.37 cc/g was treated with nitric MWI
and manganese nitrate in a 50 wt% aqueous solution, then 5
The deodorizing catalyst of Example 1 was prepared by calcining at 00° C. for 2 hours and carrying 40 g/I of a mixed compound of silver and manganese.

Example 2 Honeycomb A was additionally fired, and the total pore volume was 0.20 c c
Similarly to Example 1, 40 g/l of a mixed compound of silver and manganese was supported on Honeycomb B, which had a concentration of 40 g/g, to provide the deodorizing catalyst of Example 2.

Comparative Example 1 Honeycomb B was further fired to reduce the total pore volume to 0.17.
Comparative Example 1 was obtained by preparing a catalyst under the same conditions as in the example using honeycomb C reduced to cc/g.

FIG. 2 shows the pore distribution of the honeycombs used in Example 1, Example 2, and Comparative Example 1.

Each honeycomb has a different total pore volume, so the peak size of the pore distribution is different, but the radius ranges from 1.000 to 30.0
There are many honeycombs having pores in the range of 0.00 to 0.00, and the total volume of pores within this range accounts for 80% or more of the total pore volume.

Comparative Example 2 and Comparative Example 3 Figure 3 shows the pore distribution of Honeycomb D and Honeycomb E. For Honeycomb D and Honeycomb E, the particle size of the cordierite raw material was adjusted so that the pore distribution was different from Honeycomb B, and the firing conditions were changed so that the total pore volume for Honeycomb D was 0.21 cc/g;
Honeycomb E is a honeycomb with a density of 0.20 c c / g, which is the same as honeycomb B.

Honeycomb D uses raw materials with relatively fine particle size, so
The pore distribution has more pores with a smaller radius than honeycomb B;
The population is concentrated between 00 and 5,000. On the contrary, honeycomb E used a raw material with a relatively coarse particle size, so the pores were concentrated between radii of s, ooo and so, ooo.

Comparative Example 2 and Comparative Example 3 were prepared by using both honeycombs to support a mixed compound of silver and manganese under the same conditions as in Example 2.

Table 1 shows the characteristics of the honeycomb prepared above.

Table 1 and Figure 4 show Example 1 in which the total pore volume of the honeycomb is 0.37cc/g, Example 2 in which the total pore volume of the honeycomb is 0.20cc/g, and 0.17c.
The temperature characteristics of the deodorizing performance of Comparative Example 1 of c/g are shown. Although the honeycombs of each catalyst differ in total pore volume, the pore distribution is similar and the radius ranges from 1,000 to 30,000.
The volume of human pores accounts for more than 80% of the total pore volume.

In order to evaluate the performance of the deodorizing catalyst, acetaldehyde was selected as the odor component, air containing 1100 pp of acetaldehyde was brought into contact with the catalyst at an air velocity of 30.0 OOh-', and the removal rate of acetaldehyde was measured.

There is no particular difference in the catalyst temperature at which acetaldehyde begins to be removed, but there is a difference in the catalyst temperature required to completely remove acetaldehyde. Comparing the temperature, Example 1 and Example 2 are 1
The temperature is around 80°C. On the other hand, in Comparative Example 1, the temperature reached 220°C, making it clear that the total pore volume affects the performance of the catalyst, and that the value needs to be at least 0.20 cc/g.

Figure 5 shows Comparative Example 2 in which the radius of pores that account for 80% or more of the total pore volume ranges from 600 to 5,000 people in order to investigate the influence of the pore distribution of the honeycomb on the performance of the deodorizing catalyst. , same<1,000 to 30,000 people Example 2
The temperature characteristics of the deodorizing performance of Comparative Example 3 were compared between <8,000 and 80,000 people. As a result, a high acetaldehyde removal rate was obtained in Example 2 at the lowest catalyst temperature, and as a result, Comparative Example 2, which had many small-diameter pores, and Comparative Example 3, which had many large-diameter pores, Since a higher temperature is required, it has been found that honeycombs such as Honeycomb A and Honeycomb B are suitable for the pore distribution of honeycombs used in the catalyst.

The deodorizing catalyst of this embodiment is used not only for food cooking devices but also for reducing or removing odor components contained in smoke and exhaust gas generated from heating devices such as garbage incinerators and painting devices.

[Effects of the Invention] According to the present invention, since the low-temperature activity of the deodorizing catalyst is improved, the catalyst preheating mechanism of the device incorporating the deodorizing catalyst can be omitted or reduced, and the device can be made smaller and lighter. Moreover, the energy consumed by the preheating mechanism can be reduced. Furthermore, since the deodorizing catalyst has high peeling resistance, the catalyst carrier does not peel off.

[Brief explanation of drawings]

Figure 1 is an external view of a porous cordierite honeycomb used in Examples and Comparative Examples of the present invention, and Figure 2 is a detailed view of the honeycomb used in Example 1, Example 2, and Comparative Example 1 of the present invention. Figure 3 shows the pore distribution of the honeycombs used in Comparative Example 2 and Comparative Example 3. Figure 4 shows the pore distribution of the honeycombs used in Example 1, Example 2, and Comparative Example 1 of the present invention. FIG. 5 is a diagram showing the temperature characteristics of the deodorizing characteristics of Example 2, Comparative Example 2, and Comparative Example 3 of the present invention. Applicant Babcock-Hitachi Co., Ltd. Agent Patent attorney Takayoshi Matsunaga and one other person Diagram Pore radius (in) Diagram Catalyst temperature (''C) Unit: mm Pore radius (person) Degrees (°C)

Claims (2)

[Claims] (1) Active ingredients containing silver and manganese elements or their compounds in deodorizing catalysts that reduce or remove odor components contained in smoke and exhaust gas generated from heating equipment such as food cookers, garbage incinerators, and painting equipment. , the total pore volume is 0.
20cm^3/g or more, radius 1,000Å to 30,0
The total volume of pores in the range of 00 Å is 80 Å of the total pore volume.
A deodorizing catalyst characterized in that it is supported on a porous material made of cordierite, mullite, alumina, etc. having a pore distribution of vol% or more. (2) A heating device characterized in that the deodorizing catalyst according to claim 1 is disposed in an exhaust section.